Former world number one Djokovic saved four match points but cracked under his opponent's tremendous pressure on the fifth as Goffin set up a last-four meeting with claycourt king Rafa Nadal who beat Argentine Diego Schwartzman 6-4 6-4.

Nadal is looking to clinch a record-extending 10th Monte Carlo title.

Earlier, Spanish claycourt specialist Albert Ramos followed up his victory over world number one Andy Murraywith a 6-2 6-7 (5) 6-2 defeat of Croatian fifth seed Marin Cilic.

France's Lucas Pouille made a fast start before being made to work harder by Uruguay's Pablo Cuevas, eventually winning 6-0 3-6 7-5.

In the first European claycourt tournament of the season, Serbian second seed Djokovic was overwhelmed in a one-sided opening set before playing more patiently in the second, but Goffin put on a gritty display in the decider.

Djokovic was serving at 4-3 but Goffin won the game to love to roar back into contention, taking every opportunity to unsettle the French Open champion.

In the 12th game, Goffin opened a 40-15 lead on Djokovic's serve but the 12-times grand slam champion saved four match points before netting a forehand to lose to the Belgian for the first time in six meetings.